Between 2004 and 2010 Peter Zellner, as principal of ZELLNERPLUS, designed and built over 15 notable public and private art galleries on both coasts. These  included the Matthew Marks, Night, LAXART, MCKunst/The Project, Kinkead Contemporary, Mark Moore and Vielmetter galleries in Los Angeles and the Maccarone, Wallspace, Zach Feuer and Harris Lieberman Galleries in Manhattan.  At UC Riverside Zellner designed the Sweeney Gallery.  ZELLNERPLUS also designed three national art fairs, artist studios for Seth Ferris and Walead Beshty and collaborated on  public and private art installations with artists such as Ellsworth Kelly, Piero Golia, Ruben Ochoa, Anton Vidokle, Yunhee Min and Kori Newkirk.